This invention relates to lithography and more particularly to developer free positive tone lithography by thermal direct write.
Laser spike annealing (LSA) is a prior art alternative to standard thermal treatment in semiconductor technology.1 In this technique, a high intensity continuous wave (CW) or pulse laser is rapidly scanned across an absorbing surface, such as a silicon wafer. As semiconductor materials generally possess high thermal conductivities, the local temperature at the laser spot spikes to a high value and then, once the laser light is removed, very rapidly drops back to ambient temperature. As a result, both the temperature and annealing time can be precisely controlled by selection of laser intensity and exposure time. Additionally, annealing can be performed while kinetically avoiding unwanted effects, such as diffusion of the gates. More recently LSA has been applied to the annealing of soft materials for the phase separation of block copolymers (BCPs)2 and chemically amplified resist (CAR) post-baking.3 
An object of the present invention is to turn prior art broad-focus LSA into a tightly focused direct write technique, as we have recently reported.4 